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2024-11-11

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It’s time to admit that genes are not the blueprint for life (www.nature.com)

submitted 11 months ago* (last edited 11 months ago) by [email protected] to c/[email protected]

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Review of 2023 book: How Life Works: A User’s Guide to the New Biology Philip Ball. ISBN9781529095999

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[–] [email protected] 1 points 11 months ago (11 children)

If there is a random mutation that is neither advantageous nor disadvantageous, wouldn't that be junk DNA?

Are we going to say we need to see how every descendant of the creature fares before we can decide whether it was junk DNA or not?

[–] [email protected] 2 points 11 months ago (5 children)

I don't know too much about the subject, but maybe this almost 30 year old article can help. There's more specific examples in the article, but this quote captures the direction:

"I don't believe in junk DNA," said Dr. Walter Gilbert of Harvard University, a pre-eminent theoretician of the human genome. "I've long believed that the attitude that all information is contained in the coding regions is very shortsighted, reflecting a protein chemist's bias of looking at DNA." Coding regions may make the proteins that are dear to a chemist's heart; but true biologists, he added, know that much of the exquisite control over these proteins is held offstage, nested within the noncoding junk.

[–] [email protected] -2 points 11 months ago (2 children)

@TempermentalAnomaly @morphballganon
Junk dna was junk science from the start for ignoring that evolution often eliminates or reduces useless things, like eyes in cave fish, so there’s little likelihood that there’s useless parts of the genome.

[–] Meowoem 6 points 11 months ago (1 children)

But it doesn't do that instantly and it does it for good reason, eyes and the sections of the brain using them require energy and are vulnerable to infection so in situations where they don't provide an advantage they increase the likelihood of death before breeding thus giving any offspring born with less energy devoted to eyes has a small advantage which over s very long time results in them being selected away.

So unless the creatures reach a perfect form for their environment then they'll always be in the process of changing and have some of the old junk in there. Also if the formerly useful part doesn't make any real difference to survivability there's no force driving it to be selected away from, it might eventually be removed by lots of pure chance events but that's going to take a huge amount of generations meaning the middle time where there's junk not yet removed us going to be very long

[–] [email protected] 1 points 11 months ago

@Meowoem
Agree that genome reduction is the slower process, but it’s part of genome evolution, not only the more “energetically expensive” parts.

“Quantitatively, the evolution of genomes appears to be dominated by reduction and simplification, punctuated by episodes of complexification.”

https://onlinelibrary.wiley.com/doi/10.1002/bies.201300037

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